This invention generally relates to detection of chemical and biological substances by a light scattering probe and a chemical sensor.
Light scattering methods such as Raman spectroscopy are known to be capable of identifying chemicals and biological agents. A major limitation associated with Raman spectroscopy is that the Raman scattering signals from chemicals and biological agents tend to be very weak. Although many attempts have been made to increase Raman scattering intensity, such efforts have not yielded practical and economical detectors based on Raman spectroscopy. As a result, Raman scattering so far only has very limited applications in sensing chemicals and biological agents.
A need therefore continues to exist for effective and practical spectroscopy-based detectors for trace amount of chemical or biological substances.